The invention relates to a driving mechanism for an exposure carriage of a copying machine which has an endless drive chain traveling over two chain cogs or wheels. A carrying pin is arranged in the drive chain which engages into a connecting link of a carrying lever of the exposure carriage, which connecting link extends transverse to the travel direction of the chain.
In a copying machine it is as a rule desired that also in the event of a disturbance of the driving mechanism that the exposure carriage can be brought to its end position into which it can be manually displaced. According to a known copying machine with a driving mechanism of the above-mentioned kind, described in German Unexamined Published Patent Application No. (DE-OS) 26 06 458, it is therefore provided to have clutch elements in the driving mechanism against which the exposure carriage can be brought manually to its end position also during a disturbance in the driving mechanism.
The invention is based upon the problem to so simplify a driving mechanism of the above-mentioned kind that clutch elements or the like are not needed and that however, the exposure carriage can be brought manually to its end position during a disturbance of the driving mechanism.
This problem is thereby solved by providing a detachable connection between the carrying pin and the carrying lever.
Through the arrangement of the invention, it is possible to interrupt the carrying connection between the exposure carriage and the chain so that the exposure carriage can be moved independently of the chain. Expensive clutch elements, one way clutches, locking devices or the like, are not necessary. It is furthermore contemplated in certain preferred embodiments of the invention to connect the chain drive mechanism directly fixedly at a driving motor.
In further arrangements of preferred embodiments of the invention, it is provided that the carrying lever is movably arranged at the exposure carriage so that it can be movable away from the carrying pin. It is advantageously provided according to certain embodiments that the carrying lever is resiliently biased with a loading spring towards its operational position. Thereby it is assured that the connection between the carrying lever and the chain is not automatically released or loosened.
In further developments of preferred embodiments of the invention, it is provided that the carrying lever is provided with inlet bevels for the carrying pin in the region of both outer sides of the connecting link or slot. Thereby, it is assured that during a switching on of the driving mechanism the carrying pin is automatically latched into the connecting link of the carrying lever so that the driving connection with advancing of the carrying pin after an advancement against the carrying lever is automatically achieved so that the chain can catch the lever with the carrying pin in each desired position.
In an especially advantageous embodiment of the invention, it is provided that the carrying lever is fastened by means of a leaf spring at the exposure carriage, which leaf spring is movable in the direction transverse to the travel direction of the exposure carriage. Such a leaf spring offers the advantage that on the one hand it can transfer without further requirements the necessary forces for the driving of the exposure carriage, while on the other hand it permits selective movement of the carrying lever in the direction transverse thereto, without requiring an auxiliary linkage or a hinge or the like to be provided.
In further arrangements of the invention, it is provided that the carrying lever extends upwardly above the exposure carriage with a gripping flange. Thereby the carrying lever is accessible from the outside without further requirements so that also an unskilled person can release the connection between the exposure carriage and the chain in order to bring the exposure carriage to the end position. This is especially advantageous, especially with a small compact copying device of the type for which the driving mechanism for the exposure carriage is adapted especially advantageously wherein elimination of the disturbance is not to be carried out at the location of the installation. Such copying machines would as a rule be sent back to the factory or the workshop of the technical customer service unit. For this purpose the exposure carriage should be moved to its end position in order to facilitate the insertion of the copying machine into the original packing.